Tube coupling



Oct. 25, 1949.

Original Filed June 26, 1946 F. A. KANE, JR Re. 23,157

TUBE CGUPLING 2 Sheets-Sheet 1 WWW/f INVENTOR.

.FRANK A. XAN; JR.

Oct. 25, 1949. F. A.KANE, JR Re. 23,157

TUBE CCUPLINGv Original Filed June 26, 1946 2 Sheets-Sheet 2 jig- Z I lNVENToR.

FRANK A KANE' JR.

l BY

A rromvff Reissues! Oct. 25, 1949 TUBI OOUPLING Frank A. Kane, Jr., Fairfield, Conn.

No. 2,466,817, dated April l. 1949, Serial No. 679,816, June 2G, 1046. Application for rei-ne August 25, 1940, Serial No. 112,382

'l Claims. (Cl. 285-122) This invention relates to tube fittings, particularly to couplings for tubing of comparatively ductile or malleable material such as copper, aluminum. or other deformable metal.

The invention is primarily adapted for use with that class of ttings of the above-mentioned category wherein a ilared end of the tube is clamped between a pipe connection (such as a threaded adapter) and a coacting nut member. so that the tube and pipe connection will together form a rigid and axially aligned unit. The invention is particularly adapted for use with the conventional arrangement above described containing a sleeve or ringdisposed around the flared tube terminal and maintained thereagainst by the nut member.

In many joint structures of the conventional type above referred to, there is insufficient grip between the component parts, so that it is a 4common occurrence for the fitting to become loosened at the joint under stress, such as would result from a bending of thetube in the region of the fitting. Such a loosening eect not only .causes an undesirable structural weakness, but

also renders the joint subject to leakage. Due to the dangerous consequences of such leakage. especially where explosive gases are to be conveyed, official approval by underwriters or similar institutions has been very frequently withheld in the case, of many fittings of the abovementioned conventional type.

It is accordingly primarily within the contemplation of this invention to eliminate the shortcomings prevalent in many commercial coupling fittings by providing a joint structurally reinforced at its weakest point. with sumcient grip between the engaged members to prevent a displacement of any of such members when the device is subjected to severe working stresses, and consequently to obviate the danger of gas or liquid leakage.

In the production of a reinforced and leakproof joint, it is a further object of my invention to avoid the danger of grinding down or thinning the wall of the tubing or otherwise mutilating the tubing. And in this aspect of my invention, it is a further object to keep the nut member out of engagement with the soft tube material, so that the operative turning of the nut will cause no damage to the tubing.

It is another object of this invention to enable the nut member. upon an operative rotation thereof when in threaded engagement with the pipe connectiomio effect a swedging action to the flared tube end while the tube is being atto maintain the sleeve and tubing in axial align ment with the pipe connection.

It is a further object of my invention to provide positive means for forcing the sleeve into operative engagement with the flared end of the tube and the pipe connection, thereby producing an effective swedging action. And it is within the contemplation of this invention to supplement said positive action with a two-point engaging arrangement, that is. with an arrangement during the swedging action whereby the sleeve is engaged at the rear and at the front regions thereof, thereby further aiding an axial alignment between the sleeve and tubing and the pipe connection. y

In the accomplishment of certain of the objectives of this invention, it has been within my contemplation to provide a pipe fitting having an annular recess with an inner inclined wall. a tubing with a flared end, a sleeve with inner and outer inclined wall, wherein the mutually engaging surfaces will, during the swedging action above referred to. cause certain deformations in the tubing and the thin forward and rear ends of the sleeve, to produce a close frictional engagement between the contacting members. and a lock-nut action that will hold the members against displacement due to vibration or mechanical stresses, all as will more fully hereinafter appear. And it has also been within my contemplation to make the said annular recess. flared tube end and forward sleeve terminal of such relative proportions that the sleeve and i'lared end will readily enter the annular recess, and yet under the said swedging action will be in pressing engagement, to enhance the scali!!! effect.

It is a further object of this invention to enable a given tting to be adaptable for use with tubing of various wall thicknesses.

v aan? And a further object of my invention is to provide a simple and easily fabricated' -device capable of attaining the objectives aforesaid.

Other objects, features and advantages will appear from the drawings and the description hereinafter given. r

Referring to the drawings,

Figure 1 is a part sectional, part elevational view of the component members of my invention,

4 shown in partially assembled relation.

showing the relative position of the members, ac- Y cording toFigure 5, and

Figure? is an elevational view of the assembly of Figure 5.

In the embodiment of my invention shown in as viewed in the drawing) axis of the tube, is less than the inclination of the rear inner conical wail Il of the nut. Satisfactory results are obtained when these inclinations are 12 and 13, respectively. In the mentioned preferred relationship, the inclination of the forward inner conical surface 2l of the sleeve, relative to the horizontal, is less than the inner conical surface 2l .of annular recess Il of connector Il.V Satisfactory results are obtained when these inclinations are 19 1A" and 20, respectively. In the mentioned preferred relationship, the inclination of the ared portion Il of the tube, relative. to the horizontal, is less than the inclinations of both the forward inner conical surface 24 of the sleeve and the inner conical surface 22 of the annular recess. In the preferred relationship, the inclination of dared end -Il isv 1415. It is also preferred that the diameter of the outer cylindrical surface 25 of the sleeve be slightly ls than -that of the outer cylindrical surface 22 of the4 annular recess, so that there is a clearance space 25 bethe drawings, the tube III, which may be copper,

aluminum or other deformable metal, is to be joined to the pipe connection or adapter II over lthe forward threaded portion I2 of which a pipe (not shown) is to be secured. Although the adapter is shown with an outer thread I2 for receiving the pipe, it may, within the scope of this invention, be ofthe female type having an internally threaded wall for receiving the pipe or other suitable fitting.

In the preferred method of practicing my in vention, a locking member or nut I3 and a sleeve Il forwardly thereof are placedy upon the tube I0, as shown in Figure 1. The forward portion of sleeve Il is internally recessed by a conical surface 2l which forms a tapered vwall portion 2I. Then, by any suitable means, the forward end I5 ofthe tube is ared outwardly a predetermined amount, whereby it will be adapted to enter an annular recess I5 provided in the end wall of adapter II. -Thereafter the said. flared end I5 of the tube and the tapered forward portion 2I of sleeve Il are inserted in the recess I8, after which the nut I3 is moved forwardly along the tube and into threaded .engagement with rear portion Il of the adapter. Upon an operative rotation of the nut I3, an inner conical wall I8 provided in the rear portion of the locking member or nut Il will engage an outer conical surface Il provided in the rear portion of the sleeve to form a tapered wall portion 20, press said rear tapered wall portion 2li slightly into the relatively soft metal of the contiguous tube, and urge the tube and sleeve assembly into the said annular recess I8 of the adapter II, all in a manner tween the sleeve and outer recess wall before the final swedging operation. I have found that a clearance of from .0015 to .003" produces satisfactory results. It is, however, understood, that angles, proportions and relationship of parts other than those hereinabove specied may be used, within .the scope and intent of lmy invention.

For best operative results, and to attain one of the important objections of my invention, the

rear aperture 21 of the nut or locking member I3 is lof greater diameter than that of thertube I0, so that the interior surface 28 of the nut will at all times be removed from the tube. The arrangement is hence such that the nutis inengagement only with the adapter and the sleeve, and always out of engagement with the tube, so that the nut will never, during the operative rotation thereof, grind, cut into or otherwise mutilate the relatively soft tubing.

An important feature of Amy .invention isthe positive means for effectuating a swedging action to be more fully hereinafter set forth. The opouter tapered surface I! of the rear portion of the sleeve, relative to the longitudinal (or horizontal upon the portions of the tube and sleeve inserted within the annular recess I6. This is accomplished by means of the circumferential protuberance or ridge 29 on the outer surface of the 4sleeve I4, preferably at the juncture of the cylindrical surface 25 and the tapered surface lI8. During the forward movement of the nut'when it is operatively rotated, the corner portion 30 of the conical wall II engages the said ridge 29, and urges it forwardly, so that both the sleeve and the tube (in the manner aforesaid) are moved forwardly towards the adapter. This positive arrangement is much more direct and effective than those conventional methods employing the in- -direct action of frictional means.

The functioning of the tapered wall portion 2| at the forward end of sleeve I4 is as follows: Tapered sleeve portion 2l and the flared en d I5 of the tube conjointly enter the annular recess I6, the cylindrical outer surface 22 of the recess being 'somewhat larger in diameter than the outer cylindrical surface 25 of sleeve I4 to permit conjoint entry into the annular recess, as shown in Figure 4,. As the sleeve and tube I0 are moved longitudinally forwardly toward connector I I (by the nut I3, as already described), the tapered sleeve portion 2I and flared end I5 of the tube are conjointly forced further into annular recess I6, vas shown in Figure 6. By reason of its tapered construction the portion 2l is forced outwardly, bendingin the region of its proximal end where it Joins the thick wall of the sleeve proper. This sauf press nt withouter cylindrical surface Il of the annular 1recess, as shown in Figure 6. This outward bending of tapered portion Il is caused, in the forward movement of the sleeve and tube. by the inner conical surface 2l of the annular recess, the outward bending pressure being transmitted through the flared end Il of the tube interposed between conical surface Il and tapered portion 2i, as shown inFigure 8. The reason for giving the forward inner conical surface 24 of the sleeve an inclination' relative to the horizontal less than the inclination of the inner conical surface 23 of the annular recess is as follows:4 As the tapered sleeve portion Il andfiared end il con- Jointly advance into annular recess il, the aforesaid outward bending pressure (transmitted through the interposed flared end Il) is at firstapplied at the distal or forward end of the tapered out the abutting surfaces 24 and Il.

The reason the inclination of flared end i5 of the tube is less than the inclinations of the inner conical surface 24 and the inner conical surface 2l of the annular recess is as follows: The hold imposed on the tube against axial pulling away or loosening by bending stress on the tube and the tightness of the seal in the annular recess of the connector will be improved by increasing the inclination of the flared end of the tube. The arrangement described permits the flared end of the tube to be given an inclination greater than usually present in such devices heretofore made, and also-assures that the tube end is flared uniformly at all points of its periphery. Moreover, the tube end is flared in two steps or stages, viz., an initial flaring (inclination of l4l5) after the sleeve and nut are placed on the tube, see Figure l and Figure 4, and a final flaring (inclination of 20) at the time the flared end of the tube and the forward tapered portion of the sleeve 4are forced tight into the annular recess, see

Figure 6. The two-stage flaring of the tube is of special importance in view of the large angle of inclination to which the tube end is flared; the tube might be too severely strained were it attempted to flare its end to this extent in one operation. With sumciently small angles, or tubes of relatively thin or malleable walls, the

induced strain would obviously be less, and the use of preflated tubing would be entirely unnecessary.

The functioning of the tapered wall portion 20 at the rear end of sleeve I4- is as follows: As the inner conical wall Il of nut Il engages the outer conical surface Il at the rear of the sleeve and the nut is advanced forwardly, to the left in Figure 4, a downward or innerward pressure is imposed by conical wall il of the nut upon the rear tapered wall portion Il of the sleeve. By reason of its tapered construction the portion 20 is forced inwardly,l bending in the region of its proximal end where it joins the thick wall of the sleeve proper. This inward bending of tapered portion 2l causes the rear portion of the sleeve to eii'ect a tight press fit with the tube, by reason of which fit both the sleeve and the tube are moved conjointly forwardlv (to force the forward tapered portion 2i' and thefiared end i6 of the tube into the annular recess Il, as already described). The

reason for giving the rear outer conical surface I4 of the sleeve an inclination 4relative to the horizontal .less than the inclination of the inner conical wall Il of the nut is as followsz'As the nut is threaded forwardly, Figure 4, the aforesaid inward bending pressure is 'at first applied at the distal or rear end of tapered wall portion 20, as shown in Figure 4, due to the smaller angle of inclination of its conical surface i8. As advancement of the nut and inward bending of lil continue, the point, or rather area, of application of the inward bending pressure progresses toward the proximal end of 20 until in the final position shown in Figure 6 the pressure is applied throughout the abutting surfaces Il and I9.

In the above description, the invention has been disclosed merely by way of example and in preferred manner; but obviously many variations and modifications may be made therein which will still be comprised within its spirit. It is to be understood, therefore, that the invention is not limited to any specific form or manner of practicing same, except in So far as such limitations are specified in the appended, claims.

I claim:

1. In a coupling device for tubing having an outwardly flared. end portion, a connector member having an end wall provided with an annular recess with -an inner conical wall inclined to the tubing axis, a sleeve disposed about the said tubv ing and having a forward inner conical surface and a rear outer conical surface, a protuberance on said outer conical surface, the said .flared end of the tubing and the forward portion of the sleeve being proportioned to conjointly enter the said annular recess of the connector member, the recess being proportioned to accommodate said flared end and forward portion from their assembled initial position'at the rear 'entrance of the recess to a final assembled position forwardlythereof, the inclination of the said forward inner conical surface of the sleeve relative to the tubing axis being greater than the inclination of the outer flared surface of the tubing when at said initial position, whereby a substantially conical space is formed between the forward end of the sleeve and the flared end of the tubing, the inclination of the inner conical wall of the said y recess relative to the tubing axis being greater than the inclination of the inner flared surface of the tubing at said initial position, whereby a substantially conical space is formed between the flared end of the tubing and the said inner conical wall; further provided with a locking member cooperating with the said connector member and having an internal conical surface inclined tothe tubing axis to provide a tapered wall portion, said wall portion being slidably engageable with said rear outer conical surface of the sleeve, the forward edge of said wall portion being engageable with said protuberance, the inclination of said tapered wall portion relative to the tubing aan? y REE /sgv egg,

position, whereby a substantially conical ia formed between the forward end of the the iiared end of the tubing, the insleeve when thetubing and sleeve are at the said initial position, whereby a substantially conical space is formed between the wall portion and rear end of the sleeve,

8. In `a coupling device for tubing having an outwardly flared end portion, a connector member having an end wall provided with an annular recemwithaninnerconicalwallinclinedtothe tubing axis. a sleeve disposed about the said tubing andV having a forward inner conical surface` and a rear outer conical surface, the-said flared end of the tubing and the forward portion of the sleeve being proportioned to conjointly enter the said annular recess of the connector member, the recess being proportioned to accommodate said ared end and forward portion from their assembled initial position at the rear entrance of the s Y i tranceoftherecesstoannalassexnbledposition forwardly thereof, the inclination of the inner conical wall of the said recess relative to the tubing axis being greater than the inclination of the inner flared surface of the tubing at said' I outer conical surface of the sleeve.

5. In a coupling device for tubing having an end portion, a connector member having an end wall provided with an annular recess with an inner conical wall inclined to the tubingsaxiaa sleeve disposed about the said tubing and having a forward inner conical surface and 'a rear outer conical surface, the said end of the tubing and the forward portion of the sleeve being proportioned to conjointly enter the said annular recess of the connector member, the recess being pro- Portioned to accommodate said end and forward portion from their assembled initial position at the rear entrance of the recess to a final assembled position forwardly thereof, further provided with a lockingvmember cooperating with the said connector member and having an internal conical surface inclined to the tubing axis to provide a tapered wall portion, said wall portion being slidably engageable with said rear outer conical surface of the sleeve, the inclination of said' tapered wall portion relative to the tubing axis being greater than the inclination of said rear outer conical surface of the sleeve when the thereof. the inclination of the said forward inner conical surface of the sleeve relative to the tubing axis being greater than the inclination of the outer flared surface of the tubing when at said initial position, whereby a substantially conical space is formed between the forward end ofthe sleeve and the flared end of the tubing, further provided with a locking member cooperating with the said connector member and having an internal conical surface inclined to the tubing axis to provide a tapered wall portion, said wall portion being slidably engageable with said rear outer conical surface of the sleeve.

A 4. In a coupling device for tubing having an outwardly flared end portion, -a connector member having an end wall provided with an annular recess with an inner conical wall inclined to the tubing axis, a sleeve disposed about the said tubing and having a forward inner conical surface and a rear outer conical surface, the said flared date said flared end and forward portionfrom their assembled initial position at the rear entubing and sleeve are' at the said initial position,

whereby a substantially conical space is formed between the wall portion and rear end of the sleeve. i

6. In a coupling device for tubing having an end portion, a connector member having an end wall provided with an annular recess with an inner conical wall inclined to the tubing axis, a

sleeve disposed about the said tubing and having a forward inner conical surface and a rear outer conical surface, a protuberance on said outer conical surface, the said end of the tubing and the forward portion of the sleeve being proportioned to conjointly enter the said annular recess of the connector member, the recess being pro- Portioned toaccommodate said end and forward portion from their assembled initial position at the rear entrance of the recess to a final assembled position forwardly thereof, further provided with a lockingsmember cooperative with the said connector member and having an internal conical surface' inclined to the tubing axis to provide a tapered wall portion, said wall portion being slidably engageable with said rear outer conical surface of the sleeve, the forward edge of said wall portion being engageable with said protuberance.

'1. In a coupling device for pipe, two complementary members in coactive threaded engagement, and a sleeve; one of said members having lan annular transverse wall with an annular recess therein presenting a cylindrical outer surface and an opposing inner conical surface' inclined tothe pipe axis, the sleeve being disposed about said pipe, the forward end of the sleeve being adjacent said annular recess and being internally and conically recessed to provide a forward tapered wall portion, the rear of the sleeve having a conical outer surface inclined to the pipe axis toprovide a rear tapered wall portion, the sleevehaving intermediate its ends an outer circumferential flange: the other of said two complementary members having an internal conical surface inclined to the said pipe axis and an annular shoulder forwardly thereof, said lastmentioned internal conical surface being engageable with the said rear tapered wall portion of the sleeve, said shoulder being'engageable with said flange, wherebyupon a rotation of one of said members relative to the other to 10 operatively draw them together, the sleeve will be forced forwardly by the resulting pressure on both its said rear tapered wall portion and its said flange, the forward end of the pipe and the said lforward tapered wall of the sleeve being forced, upon said drawing together of said complementary members, to conjointly enter the annular recess, whereby a tight press fit of the tube and sleeve both within the recess and in l0 the region of the said flange will be eil'ected.

FRANK A. KANE, JR.

No references cited. 

